Prince died of an opioid overdose, according to a report from the Associated Press.

The announcement comes after weeks of speculation about what led to the performer’s death. He died on April 21 at Paisley Park, his Minneapolis-area estate.

The Midwest Medical Examiner’s Office had initially said that an autopsy conducted on Prince was inconclusive, and reported that it was waiting until a toxicology report was completed. Prince had been in possession of prescription painkillers.

The performer’s plane had made an emergency stop a week before his death so that he could check into a hospital. The Associated Press said Prince was unconscious at the time the plane landed and that first responders had administered a shot of Narcan, which offsets suspected opioid overdoses. News reports at the time said Prince was fighting the flu and possibly suffering dehydration.

Prince had been seen twice in the weeks before his death by Dr. Michael Todd Schulenberg, a family practitioner. Schulenberg told investigators he prescribed medications for the singer. It’s not known what medications were specified in a search warrant issued for the Minnesota hospital that employed the physician at the time. Schulenberg saw Prince on April 7 and April 20, the day before his death.

Since Prince’s death, it has been revealed that his friends had been attempting to get him help for his addiction. Dr. Howard Kornfeld, an addiction specialist who runs a treatment center in Mill Valley, California, had sent his son, Andrew, to Prince’s home, Paisley Park, to visit with the performer. Andrew arrived on the morning that Prince died and found him unconscious. It was Andrew who called 911.

Prince’s estate is worth millions, but he reportedly left no will. His sister, Tyka Nelson, and a Carver County judge have appointed Bremer Trust to act as a temporary special administrator for the estate. The company has already drilled open a vault that contains thousands of his recordings and is looking for a will.

Prince’s remains were cremated in a private ceremony shortly after his death.